Summer parties often involve dipping, grilling, and happily biting into fresh fruit. Here are some useful things to know about those mini-carrots perfect for dipping into guacamole or hummus, those hot dogs sizzling invitingly on the grill, and that giant watermelon waiting to be sliced. Nothing shouts summer quite as loudly as these foods.  Let's answer some FAQs about these ubiquitous treats.  Note: some questions express concerns about harmful substances in these beloved edibles.